Arama Sonuçları

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  • Öğe
    Konsantrik tip bir ısı değiştiricisinde türbülatörlerin ısı transferine etkisinin deneysel incelenmesi
    (Dicle Üniversitesi, 2013) Budak Ziyadanoğulları, Neşe; Argunhan, Zeki; Yücel, Halit Lutfi
    In this study, the effect of four different types of turbulators placed inside the pipe entrance in a concentric (nested) heat exchanger on heat transfer and pressure drop has been investigated experimentally. For this purpose, an experimental system of heat exchanger was established in which air passed through the inner tube as hot fluid whereas water passed through the outer pipe as cold fluid. Experiments have been conducted under the same and opposite directional parallel flow conditions in order to investigate the effect of turbulators that are produced as unperforated and perforated in different positions on heat transfer and pressure drop. When the research data was analysed, it became clear that maximum heat transfer happens in the inner, outer wing and body perforated turbulators.
  • Öğe
    Experimental investigation of thermal performance in a concentric tube heat exchanger with wavy inner pipe
    (SpringerLink, 2012-06) Argunhan, Zeki; Çakmak, Gülşah; Yücel, Halit Lutfi; Yıldız, Cengiz
    In this article, the heat transfer, friction factor, and thermal performance factor characteristics of a concentric-tube heat exchanger are examined experimentally. A wavy inner pipe is mounted in the tube with the purpose of generating swirl flow that would help to increase the heat transfer rate of the tube. The examination is performed for a Reynolds number ranging from 2700 to 8800. An empirical correlation is also formulated to match with experimental data of the Nusselt number using the Wilson plot method. In addition, to obtain the real benefits in using the swirl generator at a constant pumping power, the thermal enhancement factor is also determined. Over the range considered, the increases in the Nusselt number, friction factor, and thermal performance factor are found to be, respectively, about 113 %, 81 %, and 196 % higher than those obtained from a smooth-surface inner pipe.